The aim of this study was to estimate the diagnostic value of common application of CA 125 level measurement and 18F-FDG PET/CT examination in patients with a suspicion of recurrent ovarian cancer.
Patients, methods: A retrospective analysis was performed on a group of 68 patients aged 31-77 (average 57.7) with a suspicion of relapsing ovarian cancer who had CA 125 serum level measurement and PET/CT examination done with a maximum interval of 60 days.
Results: PET/CT examination result was positive in 33 patients (48.5%) and negative in 35 (51.5%). Level of CA 125 was significantly higher in women with a positive PET/CT result than in patients with a negative one (average 199.9 U/ml and 15.7 U/ml, respectively, p < 0.001). Nevertheless, comparison of CA 125 level in groups defined according to the localization of the relapse showed no significant differences. Moreover, the ROC analysis revealed that the optimal cut-off point of CA 125 concentration to predict positive PET/CT result was 17.6 U/ml. Area under the curve was 0.91. Sensitivity, specificity and accuracy in prognosticating positive PET/CT result for the selected cut-off point of 17.6 U/ml were 90.9%, 80.0% and 85.3%, respectively.
Conclusion: CA 125 level does not depend on the localization of the recurrence. PET/CT is particularly useful in patients with a suspicion of relapsing ovarian cancer with CA 125 value of at least 17.6 U/ml.
Keywords: 18F-FDG; CA 125; Ovarian cancer; PET/CT; diagnosis; recurrence.